Sheet-feeding device for printing machines

ABSTRACT

The invention relates to feeding and registering sheets to printing machines. Instead of a side lay there is arranged a measuring head, measuring the side position of the incoming sheet which is shifted away from the side lay line according to the difference of a measured value and a target value. The sheet can be shifted by a suction pulling bar or a stop drum or an intermediate drum respectively.

United States Patent n91 Bolza-Schiinemann et al.

[ SHEET-FEEDING DEVICE FOR PRINTING MACHINES [75] Inventors: Dr.-Ing. Hans-Bernhard Bolza-Schiinemann, Wurzburg; Karl-Heinz Wolfram, Eibelstadt, both of Germany [73] Assignee: Schnellpressenfabrik Koenig &

Bauer Aktiengesellschait, Wurzburg, Germany [22] Filed: Sept. 15, 1971 [21] Appl. No.: 180,752

[30] Foreign Application Priority Data Sept. 22, 1970 Germany P 20 46 602.8

[52] US. Cl. 271/58, 271/48 [51] Int. Cl B65h 9/10, B65h 9/20 [58] Field of Search 271/58, 59, 48, 49,

[56] References Cited UNITED STATES PATENTS 1,951,901 3/1934 Cottrell 271/58 July 3,1973

3,313,461 4/1967 Andersen 226/20 3,536,322 10/1970 Shimizu 271/59 3,244,418 4/1966 Henderson... 271/59 3,069,921 12/1962 Davis 226/19 X 3,431,425 3/1969 Brown et a1... 250/219 DR 3,001,788 9/1961 Vandeman 271/58 FOREIGN PATENTS OR APPLICATIONS 653,308 11/1937 Germany 271/58 Primary Examiner-Evon C. Blunlk Assistant Examiner-Bruce H. Stoner, Jr. Attorney--Harris C. Lockwood 5 7] ABSTRACT The invention relates to feeding and registering sheets to printing machines. Instead of a side lay there is arranged a measuring head, measuring the side position of the incoming sheet which is shifted away from the side lay line according to the difference of a measured value and a target value. The sheet can be shifted by a suction pulling bar or 'a stop drum or an intermediate drum respectively.

15 Claims, 6 Drawing Figures Patented July 3, 1973 m HHIHMIIII I IN 5 Sheets-Sheet 1 Fig. 7

Patented July 3, 1973 3,743,277

5 Sheets-Sheet 2 Fig.

Patented July 3, 1973 3,743,277

5 Sheets-Sheet 3 2 Fig. 4

Patented July 3, 1973 3,743,277

5 Sheets-Sheet 4 Fig. 5

Patented July 3, 1973 5 Sheets-Sheet 5 o o d o o 0 0 SHEET-FEEDING DEVICE FOR PRINTING MACHINES BACKGROUND OF THE INVENTION Numerous systems are known, with which the sheets are stream-fed to the front lays drawn to the side lay and fed by swinging or rotating pre-grippers to the impression cylinder directly or by means of an intermediate drum.

Nearly all systems have the disadvantage, that the adjusting time at the side lay is relatively short and cannot be shortened any more. Also, for this reason the speed of sheet-fed printing presses cannot be increased. This difficulty arises because the pulltype lay can pull the sheet only when the trailing edge of the preceding sheet has passed the side lay and because, on the other hand the side lay must be already open again when the leading edge of the following sheet has reached the side lay.

For increasing the sheet pulling time it has been proposed to pull the sheets by means of a suction bar acting on the underside of the sheet, but this proposal has never been realized because of the difficult suction aid adjustment.

It is known now totransfer the sheet from the side lay by a certain amount. This action must be terminated before the sheet feeding drum grips the sheet. Thus the side lay is free for the following sheet.

German Pat. specification 653.308 teaches to shift the sheet from the side lay by, means of an axial movement of the sheet feeding drum. At the time of delivery to the impression cylinder the axial movement has terminated. It amounts to approximately three/eighth inch with a pulling way of three/sixteenth inch.

SUMMARY It is the object of the invention to increase the speed of the press. The invention provides that in place of the side lay a measuring head and a controlling device are arranged which effect the shifting motion of the sheet, whereby the shifting way is individually different from sheet to sheet and is controlled according to the individual side position of the sheet after being adjusted at the frontlays so that each sheet arrives at the impression cylinder in the same and proper position.

The invention also provides a measuring head being dssigned in such a way that the side position of the sheet is picked up by a photo cell with wedge-shaped light incidence, so that a specified photo current corresponds to an appointed side position. This measuring value is automatically compared with a target value which is equivalent to the side lay line. From that results an electronic measure for the necessary side motion of the sheet.

The arrangement according to the invention is very advantageous and permits long adjusting times unknown up to this day. The time being available for adjusting the front lays or side lays is now available for the adjustment only at the front lays because the side adjustment does not disturb the sheet stream. The sheet ought not to come immediately onto the impression cylinder while being shifted by the pre-grippers or the stop drum, but it ought to run'for a longer time on the pre-gripper drum or an intermediate drum, in order to adjust the sheet side position by the measuring control. in this manner the side adjusting time known up to now can be doubled, or the efficiency of the machine can be increased by reducing the adjusting time.

Another advantage of the invention is that the groove can be formed very small because the side adjustment is independent of the length of thesheet. Up to now the length of the groove dependson the distance between the front lay and the leading edge of the sheet following on the feeding table. All cylinders of the press according to the invention can be formed essentially smaller so that the machines are cheaper to be manufactured. At the same number of sheets per hour the impression develops more slowly.

An embodiment of the invention is diagrammatically illustrated, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a side elevation of a feeding table with a pulling bar for suction feed,

FIG. 2 shown a side elevation of the feeding table andv representation of an intermediate circuit and FIG. 6 shows the suction pulling bar and its operating mechanism for transverse movement of the sheet under the control of the measuring head and intermediate control circuit.

A stop drum 1 is fed by sheets 2.1 and 2.2 respectively etc. on the feeding table 3 from the feeding stack 4. They are stopped at the front lays 5 which can be swung downwards.

According to the invention the side lay known up to now is dispensed with and, see FIG. 3, instead of the side lay a measuring head 10 is arranged on the feeding table. The side position of the sheet is measured by the measuring head 10. It may consist for example of a light source 10.1 and a photo cell 10.2. The light stream may be limited by a light window 11. Beyond this the light falling from the light source to the photo cell is partially coverd by the side edge of the sheet.

The light window 11 is shaped like a triangle, see FIG. 3. According to the different side lay of the running sheets a bigger and a smaller amount of light stream is let through to the photo cell. According to this the measuring head It) delivers a bigger or a smaller electric value, i.e. electric tension or voltage for instance.

The light source may emit a constant or a pulsing light so that the output of the measuring head may also deliver pulsing measuring values or deliver same after transformation.

The invention proposes two features to shift the sheet 2.1 from the original position to a side position in a direction away from the measuring head firstly by a suction air bar 6 acting; on the under-side of the sheet or secondly by a stop drum 1 or an intermediate drum 12 on which the sheet is gripped by gripper row 9 and by which the sheet is pulled from the feeding table.

The swinging gripper or the stop drum 1 performs beyond its usual rotating motion aside motion so that the sheet is moved on a threading line from the incoming position. Therefore the position of the sheet under the measuring head is carried out early and more free time is afforded and the position of the next sheet may be measured, though the trailing edge of the proceeding sheet has not yet passed clear of the side lay line. The gain in adjusting time is used for higher machine speed and/or for reducing the cylinder gaps.

An example of side shifting the stop drum 1 or of an intermediate drum 12 respectively is demonstrated in FIG-4.

The stop drum 1 or an intermediate drum 12 is journaled in the frames I and II and can also reciprocated axially in this journaling. One journal end has a thrust bearing 14 acting bilaterally, the stillstanding races of which are connected by a shifting piece 15. One surface of the shifting piece cooperates with an adjusting wedge 16, through which both parts 15 and 16 show the same wedge angle with respect to the axis of the stop drum 1. The adjusting wedge 16 is moved by a hydraulic cylinder 17. Pressure springs 18 reset it. A core 21 of a measuring coil 20 which is fixed to the frame is connected to the adjusting wedge 16. The shifting motion can be also performed by a hydraulic cylinder acting axially on the stop drum 1, the suction pulling bar 6 or an intermediate drum such as 12. A wedge arrangement like that shown in FIG. 4 can be used to move the suction pulling bar 6, see FIG. 6. So also such a wedge arrangement can be used with the intermediate drum 12. The position of the incoming sheets is measured by the measuring head 10. If the side edge of the sheet coincides with the position wanted, the sheet is shifted laterally by a predetermined measure. If the position of the sheet diverges from the theoretic position, it will be shifted by an amount being bigger or smaller than the predetermined value. As the sheet is shifted the measuring head 10 is set free for measuring the next sheet.

The measuring value coming from the measuring head 10 is treated and stored in an intermediate circuit, see block 23, in FIG. 5. The motion of the adjusting wedge 16 is effected by the control valve 19 controlled by the block 23 connected by lines 19.1 und 19.2. The core 21 in the measuring coil 20 causes an induction at the right position of the adjusting wedge 16 which is signaled to the intermediate circuit, see block 23, by lines 20.1 and 20.2 and which corresponds to the value predetermined by the measuring head 10.

In this position the motion of the adjusting wedge 16 is stopped by the hydraulic cylinder 17 which is controlled by the control valve 19. Then the sheet has reached the right side edge position and is delivered to the impression cylinder 13.

According to another embodiment of the invention the sheets can be delivered from the stop drum 1 to an intermediate drum 12 on which they cover a distance of about 180 to the impression cylinder 13. The stop drum 1 has grippers which disappear under the surface of the drum and has for instance the gripper systems 9 and 9.1. The intermediate drum 12 and the impression cylinder 13 have one gripper system each, see FIG. 2.

The sheet being adjusted at the front lays is pickedup by the measuring head 10. According to the measuring value the intermediate drum 12, see FIGS. 2 and 4, is shifted during its rotation and the sheet is delivered to the impression cylinder 13 in the right position.

Instead of a stop drum swinging pre-grippers can also be used.

The translation of the sheet can also be effected by a suction pulling bar, see FIG. 6, before being gripped by the grippers.

What is claimed is:

1. An apparatus for feeding and registering sheets to printing machines, the improvement comprising a measuring head means positioned in the usual position of a side lay, said sheets overlapping in the sheet feeding stream, said measuring head means being adapted to sense the side edge position of each sheet in the sheet feeding stream with respect to an established reference position and deliver a corresponding electric value, means for moving said sheet in a generally transverse direction to said sheet feeding stream in a direction away from the measuring head and to a predetermined side registered position, control means for said sheet transverse moving means, said control means being responsive to said delivered electric value and causing the required movement of said transverse sheet moving means whereby the sheet is moved to the predetermined side registered position uncovering the side edge of the next succeeding sheet for its position measuring even though the trailing edge of the first mentioned sheet has not yet passed downstream of a line extending transversely of the sheet feeding stream at said measuring head means and each sheet is fed in correct position to the impression cylinder of said printing machine.

2. Apparatus according to claim 1 including front lays for receiving each sheet and wherein said means for moving said sheet in a generally transverse direction to said sheet feeding stream is a suction pulling bar positioned to move each sheet while it is at said front lays.

3. Apparatus according to claim 2 wherein said measuring head means and said control means for said sheet transverse moving means includes an adjusting wedge means acting on said suction pulling bar and which is dislocated according to the measured values of the measuring head which limits the transverse motion of said suction pulling bar in a generally transverse direction to said sheet feeding stream.

4. Apparatus according to claim 2 wherein said control means for said sheet transverse moving means includes an electric intermediate circuit means which receives said electric value and is adapted to compute as an electric control value a difference between a desired target value for sheet positioning and said electric value delivered by said sensing means.

5. Apparatus accordig to claim 4 wherein the measuring head includes and measures the side position of the incoming sheet by a light source and a photo cell through a light window.

6. Apparatus according to claim 1 wherein said means for moving said sheet in a generally transverse direction to said sheet feeding stream is a stop drum positioned adjacent front stop lays provided in said apparatus.

7. Apparatus according to claim 6 wherein said measuring head means and said control means for said sheet transverse moving means includes an adjusting wedge means acting on said stop drum and which is dislocated according to the measured values of the measuring head which limits the transverse motion of said stop drum in a generally transverse direction to said sheet feeding stream.

8. Apparatus according to claim 6 wherein said control means for said sheet transverse moving means includes an electric intermediate circuit means which receives said electric value and is adapted to compute as an electric control value a difference between a desired target value for sheet positioning and said electric value delivered by said sensing means.

9. Apparatus according to claim 8 wherein the measuring head includes and measures the side position of the incoming sheet by a light source and a photo cell through a light window.

10. Apparatus according to claim 1 wherein said means for moving said sheet in a generally transverse direction to said sheet feeding stream is an intermediate drum positioned adjacent an impression cylinder of the printing machine.

11. Apparatus according to claim 10 wherein measuring head means and said said control means for said sheet transverse moving means includes an adjusting wedge means acting on said intermediate drum and which is dislocated according to the measured values of the measuring head which limits the transverse motion of said intermediate drum in a generally transverse direction to said sheet feeding stream.

12. Apparatus according to claim 1 wherein the measuring head includes and measures the side position of the incoming sheet by a light source and a photo cell through a light window.

13. Apparatus according to claim 1 wherein said con trol means for said sheet transverse moving means includes an electric intermediate circuit means which receives said electric value and is adapted to compute as an electric control value a difference between a desired target value for sheet positioning and said electric value delivered by said sensing means.

14. Apparatus according to claim 13 wherein the measuring head includes and measures the side position of the incoming sheet by a light source and a photo cell through a lightwindow.

15. Apparatus according to claim 1 wherein said control means for said sheet transverse moving means includes an adjusting wedge means: which is dislocated according to the measured values of the measuring head which limits the transverse motion of said means for moving said sheet in a generally transverse direction to said sheet feeding stream.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,71 77 v Dated July 3, 1973 It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 4-, line 4-8, cancel accordig and insert --according--.

Column 5, line 1%, after "wherein" insert --sai 1--; line 15, cancel the second "saidfl,

Signed and sealed this 27th day of November 1973.

(SEAL Attest:

EDWARD M.FLETCHER,JR. I RENE D. TEGTMEYER I Attesting Officer Acting Commissioner of Patents FORM Po-1oso (10-69) uscwmc 0.5. GOVERNMENT PRINTING OFFICE 1919 0-355-3 4 

1. An apparatus for feeding and registering sheets to printing machines, the improvement comprising a measuring head means positioned in the usual position of a side lay, said sheets overlapping in the sheet feeding stream, said measuring head means being adapted to sense the side edge position of each sheet in the sheet feeding stream with respect to an established reference position and deliver a corresponding electric value, means for moving said sheet in a generally transverse direction to said sheet feeding stream in a direction away from the measuring head and to a predetermined side registered position, control means for said sheet transverse moving means, said control meAns being responsive to said delivered electric value and causing the required movement of said transverse sheet moving means whereby the sheet is moved to the predetermined side registered position uncovering the side edge of the next succeeding sheet for its position measuring even though the trailing edge of the first mentioned sheet has not yet passed downstream of a line extending transversely of the sheet feeding stream at said measuring head means and each sheet is fed in correct position to the impression cylinder of said printing machine.
 2. Apparatus according to claim 1 including front lays for receiving each sheet and wherein said means for moving said sheet in a generally transverse direction to said sheet feeding stream is a suction pulling bar positioned to move each sheet while it is at said front lays.
 3. Apparatus according to claim 2 wherein said measuring head means and said control means for said sheet transverse moving means includes an adjusting wedge means acting on said suction pulling bar and which is dislocated according to the measured values of the measuring head which limits the transverse motion of said suction pulling bar in a generally transverse direction to said sheet feeding stream.
 4. Apparatus according to claim 2 wherein said control means for said sheet transverse moving means includes an electric intermediate circuit means which receives said electric value and is adapted to compute as an electric control value a difference between a desired target value for sheet positioning and said electric value delivered by said sensing means.
 5. Apparatus accordig to claim 4 wherein the measuring head includes and measures the side position of the incoming sheet by a light source and a photo cell through a light window.
 6. Apparatus according to claim 1 wherein said means for moving said sheet in a generally transverse direction to said sheet feeding stream is a stop drum positioned adjacent front stop lays provided in said apparatus.
 7. Apparatus according to claim 6 wherein said measuring head means and said control means for said sheet transverse moving means includes an adjusting wedge means acting on said stop drum and which is dislocated according to the measured values of the measuring head which limits the transverse motion of said stop drum in a generally transverse direction to said sheet feeding stream.
 8. Apparatus according to claim 6 wherein said control means for said sheet transverse moving means includes an electric intermediate circuit means which receives said electric value and is adapted to compute as an electric control value a difference between a desired target value for sheet positioning and said electric value delivered by said sensing means.
 9. Apparatus according to claim 8 wherein the measuring head includes and measures the side position of the incoming sheet by a light source and a photo cell through a light window.
 10. Apparatus according to claim 1 wherein said means for moving said sheet in a generally transverse direction to said sheet feeding stream is an intermediate drum positioned adjacent an impression cylinder of the printing machine.
 11. Apparatus according to claim 10 wherein measuring head means and said said control means for said sheet transverse moving means includes an adjusting wedge means acting on said intermediate drum and which is dislocated according to the measured values of the measuring head which limits the transverse motion of said intermediate drum in a generally transverse direction to said sheet feeding stream.
 12. Apparatus according to claim 1 wherein the measuring head includes and measures the side position of the incoming sheet by a light source and a photo cell through a light window.
 13. Apparatus according to claim 1 wherein said control means for said sheet transverse moving means includes an electric intermediate circuit means which receives said electric value and is adapted to compute as an electric control value a difference between a deSired target value for sheet positioning and said electric value delivered by said sensing means.
 14. Apparatus according to claim 13 wherein the measuring head includes and measures the side position of the incoming sheet by a light source and a photo cell through a light window.
 15. Apparatus according to claim 1 wherein said control means for said sheet transverse moving means includes an adjusting wedge means which is dislocated according to the measured values of the measuring head which limits the transverse motion of said means for moving said sheet in a generally transverse direction to said sheet feeding stream. 